Bad service from credit worx

i received a call from credit worx, for my Netstar account, of which i am fully aware of and willing to pay however i am being told the account now owes R4700. this is an account i have less than 2 years. Debiting R89.00 from my insurance. according to the invoice from Netstar i only owe R1700. This is frustrating never mind the rude call centre agents!